The invention relates to programmable sewing machines, more particularly, with a high density programming means for use for the programmable sewing machine.
Recently, there have been developed, family sewing machines having the capability to accept in a static read-write memory pattern information selected by or designed by a sewing machine operator. These recently developed programmable family sewing machines provided the sewing machine operator with the capability of producing a variety of switch patterns far beyond that provided by any heretofore known family sewing machine. An early form of such a reprogrammable sewing machine is disclosed in the U.S. Pat. No. 4,014,275 of Herr et al. Still other forms of programmable sewing machines are shown in U.S. Patents Applications Ser. Nos. 709,049 and 709,050, both filed on July 27, 1976.
In the U.S. Patent Application Ser. No. 709,049, now U.S. Pat. No. 4,085,691 there are disclosed two embodiments of a family sewing machine, one having a separable programmable memory unit and the other, an integral programmable memory unit. Access to the programmable memory unit is implemented by a plurality of selector push buttons, preferably aligned in an array of rows and columns so that an operator may visualize thereon the resultant pattern. In the application each push button generates a discrete voltage which may be encoded by an encoder into binary digits suitable for insertion into the read-write memory and subsequent retrieval therefrom and conversion to an analog form to actuate electromechanical actuators such as linear motors. In order to accomplish this each selector button may be connected to a discrete switch which creates a bulky arrangement evident in the 5.times.5 matrix of the programmable unit disclosed in the application. However, a commercially viable programmable device requires a finer resolution and lower cost arrangement than is attainable with a multiplicity of discrete switch components. Ideally, a device is required which is compact though matched in resolution capability with the resolution capabilities of an electronically controlled sewing machine to which it is attached.